A machining operation requires close tolerances on a certain part for automobile engines. The current specification for this measurement is $3\mathrm{.}0cm+-\mathrm{.}001.$ The quality control procedure is to take a sample of $4$ units and measure each of the parts. On the basis of past samples of size $4,x$ bar $=3\mathrm{.}0$ and $R$ bar $=\mathrm{.}0020.$

a$.$ Construct average and range charts for this part.

b$.$ On the basis of the following data, is the process in control?

$\backslash$table$[[$Sample$,$X bar,$R$

Please use an excel spreadsheet